EconSim

Compound Interest

Watch a lump sum grow, and see why compounding beats simple interest.

Understand how compounding makes money grow exponentially over time, and how rate, frequency, and horizon affect the outcome.

  • Time value of money
  • Exponential growth
  • Compounding frequency
  • Simple vs compound interest

Guided walkthrough

Step 1 of 3
Predict first

Raise the annual rate from 5% to 10%.

Before you act, predict what will happen. Does the final balance simply double, or more than double? Then do it — did your prediction match what happened?

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%
yr

Balance over time

Compound interest curves upward; simple interest is a straight line.